JPH09230615A - Electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a practically extremely useful electrophotographic photoreceptor having excellent sensitivity by containing a mixed crystal of a phthalocyanine compound having a specific alkylene glycolate titanium ring and an oxytitanium phthalocyanine compound. SOLUTION: A mixed crystal of a phthalocyanine compound having an alkylene glycolate titanium ring having the carbon atom number not less than four and an oxytitanium phthalocyanine compound is contained. A phthalocyanine compound expressed by a formula is used as a phthalocyanine compound having an alkylene glycolate titanium ring having the carbon atom number not less than four. In the formula, R<1> and R<2> represent respectively and independently a substitutional or nonsubstitutional alkyl group, and Pc represents a substitutional or nonsubstitutional phthalocyanine residue. Structures of respective phthalocyanine residues of these phthalocyanine compound and oxytitanium phthalocyanine compound are preferable to be the same.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copying machine, L
The present invention relates to an electrophotographic photosensitive member used in a D printer, an LED printer, or the like.

[0002]

2. Description of the Related Art In recent years, 800 nm typified by semiconductor lasers and light emitting diodes (LEDs) with the development of the electronics industry.
Copiers, LD printers that use long-wavelength light sources in the vicinity,
As a material used for an electrophotographic photoreceptor such as an LED printer, a phthalocyanine compound sensitive to these light sources has been attracting attention.

1992 Electrophotographic Society "Japan H
arducopy '92, Proceedings, pp. 153-156, Abstract of Lecture entitled "Formation and Properties of Titanyl Phthalocyanine Crystals Containing Diol Compound", and 199
3rd International Conference of Electrophotographic Society “Japan Hardco
py '93 "Proceedings, pages 659-662," SY
NTHESES AND PROPERIES OF
TITANYL PHTHALOCYANINE N
The abstract of the lecture entitled "EW POLYMORPHS" is described, and JP-A-5-273775 discloses a diol having one hydroxyl group at each two adjacent carbon atoms such as 2,3-butanediol. It is described that a compound and an oxytitanium phthalocyanine react with each other to form an addition compound, which suggests that the addition product may be used in an electrophotographic photoreceptor.

[0004]

However, when a reaction product of oxytitanium phthalarosinin and an adjacent diol compound such as 2,3-butanediol is obtained, as described in the above-mentioned three known literatures, The reaction product obtained by using an adjacent diol compound with respect to oxytitanium phthalocyanine in an excess amount such as the amount of solvent has a problem that the reaction product is a single crystal of the phthalocyanine compound having a specific structure. In use, there was a problem that sufficient sensitivity could not be obtained.

The inventors of the present invention have made extensive studies in view of the above circumstances, and as a result, an electrophotographic photosensitive member characterized by containing a mixed crystal of a phthalocyanine compound having a specific structure and an oxytitanium phthalocyanine compound exhibits excellent sensitivity. As a result, they have completed the present invention.

That is, the present invention provides an electrophotographic photoreceptor containing a mixed crystal of a phthalocyanine compound having an alkylene glycolate titanium ring having 4 or more carbon atoms and an oxytitanium phthalocyanine compound.

That is, the present invention provides the following formula (1)

[0008]

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(In the formula (1), R ¹ and R ² each independently represent a substituted or unsubstituted alkyl group, and Pc represents a substituted or unsubstituted phthalocyanine residue). And an oxytitanium phthalocyanine compound.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The electrophotographic photoreceptor of the present invention will be described in detail below. The photoreceptor of the present invention contains a mixed crystal of a phthalocyanine compound having an alkylene glycolate titanium ring having 4 or more carbon atoms and an oxytitanium phthalocyanine compound.

As the alkylene glycolate titanium ring having 4 or more carbon atoms, an alkylene group having 2 or more carbon atoms-oxygen atom having two oxygen atoms-substituted or unsubstituted alkyl groups bonded in this order, An example is a ring having a structure in which two oxygen atoms are bonded to Ti atoms.

Examples of the phthalocyanine compound having an alkylene glycolate titanium ring having 4 or more carbon atoms include a phthalocyanine compound represented by the following formula (1).

In the present invention, the following formula (1)

[0014]

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(In the formula (1), R ¹ and R ² each independently represent a substituted or unsubstituted alkyl group, and Pc represents a substituted or unsubstituted phthalocyanine residue.) The greatest feature is that it contains a mixed crystal of an oxytitanium phthalocyanine compound.

Specific examples of the structural formula of the phthalocyanine compound represented by the above formula (1) include the followings. In the formula, Me is a methyl group, Et is an ethyl group, n-Pr is a linear propyl group,
iso-Pr represents an isopropyl group, Ph represents a phenyl group, Bz represents a benzyl group, and Pc represents a phthalocyanine residue.

[0017]

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[0018]

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The phthalocyanine compound having the specific structure represented by the above formula (1) includes the following formula (2)

[0020]

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A stereoisomer (A) having a threo-type stereostructure represented by the following formula (3)

[0022]

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(In the formulas (2) and (3), R ¹ and R ² each independently represent a substituted or unsubstituted alkyl group, and Pc represents a substituted or unsubstituted phthalocyanine residue). The stereoisomer (B) having the erythro-type stereostructure shown is included, but the phthalocyanine compound having the specific structure for constituting the mixed crystal, which is the feature of the present invention, has an A / B composition ratio of 40. It is preferably / 60 or more, and more preferably 80/20 or more.

It is preferable that the phthalocyanine compound having the specific structure does not consist of only A or B.

Further, A represented by the above formula (2) includes the following formula (7)

[0026]

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A stereoisomer having an absolute structure represented by the following formula (8)

[0028]

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A stereoisomer having an absolute structure represented by the formula (3) is included, and B represented by the formula (3) is represented by the following formula (9).

[0030]

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A stereoisomer having an absolute structure represented by the following formula (10)

[0032]

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(In formulas (7), (8), (9) and (10), R ¹ and R ² each independently represent a substituted or unsubstituted alkyl group, and Pc is a substituted or unsubstituted alkyl group. A substituted phthalocyanine residue is represented by the formula (1), and a phthalocyanine compound having the specific structure represented by the formula (1) is included in the above-mentioned preferred range. It may consist of any combination selected from the group.

In the present invention, the oxytitanium phthalocyanine compound has an oxytitanium (O = Ti) group at the center of the phthalocyanine residue.

In the present invention, the phthalocyanine residue is represented by the formula (11)

[0036]

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The hydrogen atom of the benzene ring of the phthalocyanine residue may be unsubstituted or substituted, and the substituent is a halogen atom such as chlorine or bromine, or a methyl group or ethyl group. Examples thereof include an alkyl group such as a group or an alkoxy group such as a methoxy group and an ethoxy group, and the phthalocyanine residue may have a ring-extended phthalocyanine structure such as naphthalocyanine. Particularly, an unsubstituted phthalocyanine residue can be preferably used.

In the mixed crystal, which is a feature of the present invention, the structures of the phthalocyanine residues of the phthalocyanine compound of formula (1) and the oxytitanium phthalocyanine compound are preferably the same.

As a mixed crystal which is a feature of the present invention, the following formula (4)

[0040]

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A mixed crystal of a phthalocyanine compound represented by (Pc in the formula (4) represents a substituted or unsubstituted phthalocyanine residue) and an oxytitanium phthalocyanine compound is particularly preferable.

Further, the phthalocyanine compound represented by the formula (4) preferably has a composition ratio of threo-type isomer / erythro-type isomer of 40/60 or more, and 80/2.
More preferably, it is 0 or more. In addition, it is preferable that the phthalocyanine compound represented by the formula (4) does not consist of only a threo-type isomer or an erythro-type isomer.

Further, the threo-type isomer has the following formula (12):

[0044]

[Chemical 21]

A stereoisomer having an absolute structure represented by the following formula (13)

[0046]

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Although the stereoisomers having the absolute structure represented by the formula (4) are included, the phthalocyanine compound having the specific structure represented by the formula (4) is a group of these absolute structure isomers and erythro-type isomers within the above preferable range. It may consist of any combination selected from.

In the present invention, a mixed crystal is a crystal in which a plurality of types of compound molecules are irregularly or regularly arranged periodically, and two or more types of single molecules are aggregated. It is distinctly different from the mixture of crystals. It can be confirmed that it is a mixed crystal, for example, in the X-ray diffraction spectrum for CuKα, because it shows a different pattern from each single crystal of a plurality of kinds of compounds constituting it.

For example, the mixed crystal characterizing the present invention is CuK.
In the X-ray diffraction spectrum for α, the above formula (1)
Shows a different pattern from both the single crystal composed of the phthalocyanine compound represented by and the single crystal composed of the oxytitanium phthalocyanine compound.

As the mixed crystal which is a feature of the present invention, CuKα
In the X-ray diffraction spectrum for, the Bragg angle (2
θ ± 0.2 °) of at least 8.3, 24.7, 25.
Those that show a peak once are particularly preferable.

The mixed crystal, which is a feature of the present invention, has a composition ratio C / D of the phthalocyanine compound (C) having the specific structure of the formula (1) and the oxytitanium phthalocyanine compound (D) of 30.
/ 70 to 70/30, preferably 40/60 to 60/4
0, more preferably 50/50.

The mixed crystal characterizing the present invention is an oxytitanium phthalocyanine compound and the following formula (14):

[0053]

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(In the formula (14), R ¹ and R ² each independently represents a substituted or unsubstituted alkyl group) and can be conveniently obtained from the reaction with the adjacent diol compound.

Specific examples of the structural formula of the adjacent diol compound represented by the above formula (14) include the followings. In the formula, Me is a methyl group, Et is an ethyl group, n-Pr is a linear propyl group,
iso-Pr represents an isopropyl group, Ph represents a phenyl group, and Bz represents a benzyl group.

[0056]

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[0057]

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Further, the adjacent diol compound represented by the above formula (14) includes the following formula (15)

[0059]

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A stereoisomer (E) having a threo-type stereostructure represented by the following formula (16)

[0061]

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(In the formulas (15) and (16), R ¹ , R ²
Each independently represents a substituted or unsubstituted alkyl group. ), A stereoisomer (F) having an erythro-type stereostructure is included, but the adjacent diol compound for obtaining a mixed crystal that is a feature of the present invention has an E / F composition ratio of 40/60. It is preferably not less than 80, more preferably not less than 80/20. It is preferable that the adjacent diol compound represented by the formula (14) does not consist only of E or F.

Further, E shown in the above equation (15) is
Formula (17) below

[0064]

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A stereoisomer having an absolute structure represented by the following formula (18)

[0066]

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The stereoisomers having the absolute structure represented by the formula (16) are included, and F represented by the formula (16) includes the following formula (19).

[0068]

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A stereoisomer having an absolute structure represented by the following formula (20)

[0070]

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(In formula (17), formula (18), formula (19) and formula (20), R ¹ and R ² each independently represents a substituted or unsubstituted alkyl group) Although a stereoisomer having a structure is included, the adjacent diol compound represented by the above formula (14) may be composed of any combination selected from these absolute structural isomer groups within the above-mentioned preferred range.

As the adjacent diol compound used in the reaction with the oxytitanium phthalocyanine compound in order to obtain the mixed crystal characterizing the present invention, 2,3-butanediol is particularly preferable. The composition ratio of 2,3-butanediol of threo type / erythro type is preferably 40/60 or more, and more preferably 80/20 or more.

It is preferable that the 2,3-butanediol does not consist only of threo type or erythro type. Further, the threo type 2,3-butanediol includes
(2R, 3R)-(-)-2,3-butanediol,
(2S, 3S)-(+)-2,3-butanediol is included, and the erythro-type 2,3-butanediol includes meso-2,3-butanediol. The butanediol may consist of any combination selected from these absolute structural isomers within the preferred ranges given above.

In obtaining the mixed crystal which is the feature of the present invention, in the reaction between the oxytitanium phthalocyanine compound and the adjacent diol compound represented by the formula (14), the adjacent diol compound is substantially mixed with the oxytitanium phthalocyanine compound. It can be easily obtained by reacting with less than 1 molar equivalent.

That is, when an oxytitanium phthalocyanine compound is reacted with substantially less than 1 molar equivalent of the diol compound, a phthalocyanine compound having a specific structure represented by the formula (1) and the remaining unreacted A mixed crystal composed of an oxytitanium phthalocyanine compound is obtained.

Further, in the structure of the phthalocyanine compound having the specific structure, the structure of the site derived from the adjacent diol represented by the formula (14) basically retains the stereo structure of the diol compound.

In order to obtain the mixed crystal, it is sufficient to react the oxytitanium phthalocyanine compound with the diol compound, which is substantially less than 1 molar equivalent to the oxytitanium phthalocyanine compound, as described above. This can be easily achieved by a method of adjusting the amount of the diol at the time of charging, and preferably the adjacent diol compound represented by the formula (14) at the time of charging the reaction is 0.5 to 1.5 mols based on the oxytitanium phthalocyanine compound. Equivalent, preferably 0.6
It is preferable to carry out the reaction by adding ˜1.0 molar equivalent.

Even if the amount of the diol is excessive with respect to the oxytitanium phthalocyanine compound at the time of charging the reaction, the reaction time is shortened and the reaction is not carried out more than necessary. A mixed crystal can be obtained.

Further, in advance, a single crystal composed of the phthalocyanine compound having the specific structure of the above formula (1) is obtained, and then this is reacted with an oxytitanium phthalocyanine compound to reconstruct the crystal, in the same manner, It is also possible to obtain a mixed crystal which is a feature of the present invention.

The oxytitanium phthalocyanine compound that can be preferably used in the above reaction for obtaining the mixed crystal which is the feature of the present invention is a substituted and / or unsubstituted phthalocyanine residue center unless the effects of the present invention are impaired. As long as they have oxytitanium in them, and they may have any crystal form as long as the effects of the present invention are not impaired.

As examples thereof, α type, β type, αβ mixed type,
Examples thereof include substituted and / or unsubstituted oxytitanium phthalocyanine compounds of crystalline type such as γ type, Y type, and amorphous.

The method for producing these oxytitanium phthalocyanine compounds is not particularly limited. For example, a reaction between titanium tetrachloride and orthophthalodinitrile or a tetra (alkoxy) titanium such as tetra (normal butoxy) titanium. It can be produced by a reaction of titanium and orthophthalodinitrile in the presence of urea, or a reaction of tetra (alkoxy) titanium such as tetra (normal butoxy) titanium with 1,3-diiminoisoindoline.

The reaction between the oxytitanium phthalocyanine compound and the adjacent diol compound represented by the above formula (14) for obtaining the mixed crystal characterizing the present invention can be preferably carried out under heating conditions, and the reaction temperature is from 30 to The range of 300 ° C. is preferable, and the range of 50 to 250 ° C. is more preferable.

In the reaction or the like for obtaining the mixed crystal which is the feature of the present invention, various known and commonly used organic solvents can be used in combination, if necessary. Examples thereof include aromatic organic solvents such as benzene, nitrobenzene, dichlorobenzene, trichlorobenzene, and α-chloronaphthalene,
Ketone-based organic solvents such as cyclohexanone, methyl ethyl ketone and methyl isobutyl ketone, ether-based organic solvents such as tetrahydrofuran and dimethyl cellosolve, ester-based organic solvents such as ethyl butanoate and butyl lactate, aprotic polar organics such as dimethylformamide and dimethyl sulfoxide. Examples thereof include solvents, halogen-based organic solvents such as trichloroethane, monohydric alcohol-based organic solvents such as amyl alcohol and dodecanol. They are,
They may be used alone or in combination of two or more.

In addition, in the treatment such as the reaction for obtaining the mixed crystal which is the feature of the present invention, each production condition such as reaction time, solvent, purification method such as washing, crystallization method and the like can be appropriately selected and adopted. Good.

The method for producing a mixed crystal, which is a feature of the present invention, will be described by taking the reaction of 2,3-butanediol (BDO) and oxytitanium phthalocyanine (TiOPc) as an example.

In the reaction, the following reaction formula (I)

[0088]

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According to this, a phthalocyanine compound (G) having a specific structure is produced.

In the reaction, when less than 1.0 molar equivalent of BDO was reacted with TiOPc, a part of T
iOPc remains as an unreacted material. As a result, at the end of the reaction, the phthalocyanine compound of G and TiOPc are present in the system, and both of them form a characteristic crystal called a mixed crystal. The mixed crystal has a G / TiOPc composition ratio of 30/7.
0-70 / 30, preferably 40 / 60-60 / 40,
More preferably, it is composed of 50/50.

Depending on the amount of G or TiOPc in the reaction system, there will be G and / or TiOPc that do not participate in the formation of the mixed crystal, but these constitute individual crystals. At this time, as a result, a mixture of the mixed crystal and a single crystal of G or TiOPc is obtained, but in the present invention, both may be mixed as long as the effect is not impaired.

The amount of BDO substantially reacted with TiOPc in the reaction is preferably less than 1.0 molar equivalent,
0.2-0.8 molar equivalents are more preferable, and 0.3-0.
7 molar equivalents are more preferable, 0.4 to 0.6 molar equivalents are further preferable, and 0.5 molar equivalents are particularly preferable.

Although BDO has threo-type and erythro-type stereoisomers, in the reaction for obtaining a mixed crystal, the threo-type / erythro-type composition ratio is preferably 40/60 or more. , 80/20 or more is more preferable.

In obtaining the electrophotographic photosensitive member of the present invention, the mixed crystal, which is a feature of the present invention, is used alone or in a mixed system as a charge generating material or a photoconductive material having both a charge generating function and a charge transporting function. It Other charge generating materials or photoconductive materials can be used in combination as long as the characteristics of the present invention are not impaired.

As examples of such other charge generating materials, any phthalocyanine compound other than the mixed crystal, which is a feature of the present invention, can be used and is not particularly limited. Specifically, for example, a metal-free phthalocyanine compound,
Metal phthalocyanine compounds, or, for example, α type, β type,
Crystalline or amorphous oxytitanium phthalocyanine compounds such as α, β mixed type, γ type and Y type, azo pigments, anthraquinone pigments, perylene pigments, polycyclic quinone pigments, squarium pigments, etc. Can be mentioned.

Further, in the electrophotographic photoreceptor of the present invention, a charge transport material such as a hole transport material and an electron transport material can be used in combination, if necessary.

The charge transporting material used in the electrophotographic photosensitive member of the present invention is not particularly limited, and various materials can be used, for example, arylamine type,
Hydrazone-based, pyrazoline-based, oxoxazole-based, oxadiazole-based, stilbene-based, butadiene-based, thiazole-based, carbazole-based, diphenoquinone-based, arylmethane-based, tetracyanoquinone-based compounds, or poly-N-vinylcarbazole, polysilane And other polymerizable compounds.

The structures of typical compounds as specific examples of the charge transport material are shown below. The numbers in parentheses below the respective structural formulas below represent the No. of the exemplified compound.

[0099]

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[0100]

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[0101]

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[0102]

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[0103]

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[0104]

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[0105]

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[0106]

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[0107]

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Various forms of the electrophotographic photosensitive member are known, but the form of the electrophotographic photosensitive member of the present invention is as follows.
Either of them may be used. As an example, the electrophotographic photoreceptors of FIGS. 1 to 4 are shown.

The electrophotographic photoreceptors shown in FIGS. 1 and 2 have a photosensitive layer 4a or 4b composed of a charge generation layer 2 and a charge transport layer 3 provided on a conductive support 1, respectively. FIG.
The electrophotographic photosensitive member of (1) has a photosensitive layer 4c in which a charge generating material 5 is dispersed in a charge transfer medium 6 on a conductive support 1. The electrophotographic photosensitive member of FIG. 4 has a photosensitive layer 4d in which a photoconductive material 8 is dispersed in a binder 9 such as a binder resin on a conductive support 1.

The mixed crystal, which is a feature of the present invention, can be used in the production of any of the electrophotographic photosensitive members shown in FIGS.

In the case of the electrophotographic photoreceptors of FIGS. 1 and 2, the charge generating material contained in the charge generating layer 2 generates charges, while the charge transporting layer 3 receives the injection of charge and transports the charge. To do. That is, the charge necessary for light attenuation is generated by the charge generating material, and the charge is transported by the charge transport medium.

In the electrophotographic photosensitive member shown in FIG. 3, the charge generating material generates charges in response to light, and the charges are mainly transferred by the charge transfer medium. In the electrophotographic photosensitive member shown in FIG. 4, generation of electric charges and movement of electric charges with respect to light are performed by a photoconductive material.

In the electrophotographic photoreceptor of FIG. 1, fine particles of the charge generating material are vapor-deposited, or if necessary, a dispersion obtained by dispersing in a solvent in which a binder resin is dissolved is applied, dried, and then applied. The charge transporting material can be produced by applying a solution obtained by dissolving the charge transporting material alone or, if necessary, a binder resin in combination and drying.

In the electrophotographic photosensitive member of FIG. 2, a solution in which a charge transporting material is dissolved alone or in combination with a binder resin if necessary is applied on a conductive support and dried, and then the charge generating material is applied. Can be produced by vapor deposition, or by applying a dispersion obtained by dispersing the fine particles in a solvent or a binder resin solution and drying.

In the electrophotographic photoreceptor of FIG. 3, fine particles of the charge generating material are dispersed in a solution prepared by dissolving the charge transporting material alone or, if necessary, together with a binder resin, and coating it on a conductive support. It can be manufactured by drying.

The electrophotographic photosensitive member of FIG. 4 contains a photoconductive material,
It can be produced by coating a dispersion liquid in which a binder such as a binder resin is dissolved on a conductive support and then drying it.

As a method of pulverizing the phthalocyanine compound which is a feature of the present invention and acts as a charge generating material or a photoconductive material and disperses it in a binder solution, specifically, in addition to a general stirring device, a homogenizer is used. Mixer, disperser,
Examples thereof include, but are not limited to, an agitator, a ball mill, a sand mill, an attritor, and a paint conditioner.

As the coating method, for example, a coating method such as a dip coating method, a spray coating method, a spin coating method, a bead coating method, a wire bar coating method, a blade coating method, a roller coating method or a curtain coating method is used. You can

Of course, the charge generation layer may be provided by vapor deposition of the charge generation material or the like so as not to impair the morphology of the mixed crystal without using the binder resin together.

In the case of the electrophotographic photoreceptors of FIGS. 1 and 2, the thickness of the photosensitive layer is 5 μm or less, preferably 0.01 to 2 μm, and the thickness of the charge transporting layer. The length is 3 to 50 μm, preferably 5 to 30 μm. In the case of the electrophotographic photoreceptors of FIGS. 3 and 4, the thickness of the photosensitive layer is
It is 3 to 50 μm, preferably 5 to 30 μm.

The proportion of the charge transport material in the charge transport layer in the electrophotographic photoreceptor of FIGS. 1 and 2 is 5 to 100% by weight.
Is preferable, and the proportion of the charge generating material in the charge generating layer of the electrophotographic photoreceptor of FIGS. 1 and 2 is 5 to 100% by weight.
Is preferable, and a range of 40 to 80% by weight is particularly preferable.

In the electrophotographic photoreceptor of FIG. 3, the proportion of the charge transport material in the photosensitive layer is preferably in the range of 5 to 99% by weight, and the proportion of the charge generating material is preferably in the range of 1 to 50% by weight. A range of 3 to 20% by weight is particularly preferable.

In the electrophotographic photosensitive member of FIG. 4, the proportion of the photoconductive material is preferably in the range of 3 to 80% by weight, and 5 to
A range of 50% by weight is particularly preferred.

A plasticizer and a sensitizer may be used together with the binder in the production of any of the electrophotographic photosensitive members shown in FIGS.

The conductive support used in the electrophotographic photoreceptor of the present invention is, for example, aluminum, copper, zinc,
Stainless steel, chrome, titanium, nickel, molybdenum,
Metal plate or metal drum using metal or alloy such as vanadium, indium, gold, platinum, or conductive polymer, conductive compound such as indium oxide, or metal or alloy such as aluminum, palladium, gold, etc., vapor deposition Or laminated paper, plastic film, etc.

As the binder resin that can be used if necessary, it is preferable to use a hydrophobic, electrically insulating, high-molecular polymer capable of forming a film. Examples of such high molecular weight polymers include polycarbonate, polyester, methacrylic resin, acrylic resin, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl acetate, styrene-butadiene copolymer, vinyl chloride-vinyl acetate-maleic anhydride. Acid copolymer, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, styrene-alkyd resin, poly-N-
Examples thereof include, but are not limited to, vinylcarbazole, polyvinyl butyral, polyvinyl formal, polysulfone and the like. These binders can be used alone or as a mixture of two or more kinds.

Further, a surface modifier can be used together with these binder resins. Examples of the surface modifier include silicone oil and fluorine resin.

Further, a well-known plasticizer may be contained in order to improve the film forming property, flexibility and mechanical strength of the electrophotographic photosensitive member. Examples of the plasticizer include biphenyl, chloride biphenyl, o-terphenyl, p-terphenyl, dibutyl phthalate, diethyl glycol phthalate, dioctyl phthalate, triphenyl phosphoric acid, methylnaphthalene, benzophenone, chlorinated paraffin, polypropylene, polystyrene and various types of plasticizers. Aromatic compounds such as phthalic acid esters such as fluorohydrocarbons, phosphoric acid esters, halogenated paraffins and methylnaphthalene can be mentioned.

Known sensitizers can be used for the photosensitive layer. Examples of the sensitizer include triphenylmethane dyes such as methyl violet, brilliant green and crystal violet, thiazine dyes such as methyl blue, cyanine dyes, pyrylium dyes, chloranil, tetracyanoethylene, rhodamine B, merocyanine dyes and thiapyrylium dyes. Etc.

In the electrophotographic photosensitive member of the present invention, in order to improve storage stability, durability and environmental resistance, a photosensitive layer may contain a deterioration inhibitor such as an antioxidant or a light stabilizer. You can also Examples thereof include a phenol compound, a hydroquinone compound, an amine compound and the like, and specific examples include butylhydroxytoluene and the like.

In addition, various other additives may be used if necessary.

Further, in the present invention, in order to improve the adhesiveness between the conductive support and the photosensitive layer and prevent the injection of free charge from the conductive support to the photosensitive layer, the conductive support and the photosensitive layer If necessary, an adhesive layer or a barrier layer may be provided between the layers.

The materials used for these layers include, in addition to the polymer compounds used for the binder resin, casein, gelatin, polyvinyl alcohol, ethyl cellulose, nitrocellulose, polyvinyl butyral, phenol resin, polyamide, carboxy-methyl cellulose. , Vinylidene chloride-based polymer latex, styrene-butadiene-based polymer latex, polyurethane, gelatin, aluminum oxide (alumite), tin oxide,
Titanium oxide or the like can be used, and the film thickness is preferably 1 μm or less.

Further, as these layers, for example, layers in which a material such as perylene pigment is dispersed in the binder resin can be used, and the film thickness thereof is preferably 1 to 10 μm and 3 to 8 is preferable.
μm is more preferred.

If desired, a protective layer such as an overcoat layer may be provided on the photosensitive member in order to improve the strength against abrasion.

The electrophotographic photosensitive member of the present invention has the above-mentioned constitution, and as will be apparent from the examples described below,
It has excellent sensitivity.

[0137]

EXAMPLES Examples will be shown below, but the present invention is not limited to these examples. In the following examples, "part" means "part by weight".

Example 1 29.2 g of 1,3-diiminoisoindoline was dispersed in 200 ml of ortho-dichlorobenzene, 20.4 g of titanium tetra-n-butoxide was added, and the mixture was mixed with 1 under nitrogen atmosphere.
Heated at 50-160 ° C for 5 hours. After cooling, the precipitated crystals were filtered, washed with chloroform, washed with 2% aqueous hydrochloric acid solution, washed with water, washed with methanol, dried, and then 26.4 g.
(91.0%) of crude oxytitanium phthalocyanine was obtained. The X-ray diffraction spectrum of this product for CuKα is shown in FIG. It can be seen that this is β-type oxytitanium phthalocyanine.

Then, 20.0 g of this crude oxytitanium phthalocyanine was dissolved by stirring in 200 ml of concentrated sulfuric acid at 5 ° C. or lower for 1 hour, and this was poured into 4 L of water at 20 ° C.
The precipitated crystals were filtered and thoroughly washed with water to obtain a wet paste product. This is dried and powdered is C
The X-ray diffraction spectrum for uKα is in an amorphous state as shown in FIG.

Ortho-dichlorobenzene 131 in a flask
Parts, and 6.25 parts of 2,3-butanediol having a threo / erythro type composition ratio of 82/18 (0.7 molar equivalent)
Then, 8 parts of the above oxytitanium phthalocyanine-amorphous dry powder was added. The mixture was then heated to reflux for 7 hours. After allowing to cool, this was poured into 800 parts of methanol to precipitate crystals. Filtered, washed with methanol, dried and in the Mass spectrum, m
A mixed crystal according to the present invention having peaks at / Z = 576 and 648 and having the crystal form of FIG. 7 in the X-ray diffraction spectrum for CuKα was obtained.

3 parts of a mixed crystal of the obtained phthalocyanine compound,
10 parts of a silicone resin (“KR-5240, 15% xylene butanol solution” manufactured by Shin-Etsu Chemical Co., Ltd.) and 100 parts of methyl ethyl ketone were pulverized and dispersed together with glass beads in a paint conditioner to obtain a dispersion liquid. On the other hand, a polyamide resin (“CM-8000” manufactured by Toray Industries, Inc.) was dissolved in methanol and coated on an aluminum vapor-deposited polyester base to give a film thickness of 0.
A 2 μm undercoat layer was formed. The above-mentioned phthalocyanine compound dispersion liquid was applied thereon to form a charge generation layer having a film thickness of 0.2 μm.

On the other hand, the following charge transport materials

[0143]

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1 part of polycarbonate resin ("UPILON Z200" manufactured by Mitsubishi Gas Chemical Co., Inc.) and 0.01 part of silicone oil ("KF-54" manufactured by Shin-Etsu Chemical Co., Ltd.) were dissolved in 15 parts of 1,2-dichloroethane. This was applied onto the above-mentioned charge generation layer to form a charge generation layer having a dry film thickness of 24 μm to prepare a photoreceptor.

The method for producing the photoconductor is in accordance with the publicly known Japanese Patent Application Laid-Open No. 5-273775, except that the phthalocyanine crystal is replaced with the mixed crystal which is a feature of the present invention.

Example 2 2,3 having a threo / erythro type composition ratio of 82/18
-A phthalocyanine crystal containing a mixed crystal according to the present invention was prepared in the same manner as in Example 1 except that the same amount of 2,3-butanediol having the same composition ratio of 44/56 was used instead of butanediol. Obtained. This product shows peaks at m / Z = 576 and 648 in the Mass spectrum, and the X-ray diffraction spectrum of this product for CuKα is shown in FIG.

A photoconductor was prepared in the same manner as in Example 1, except that the same amount of the obtained phthalocyanine compound crystal was used instead of the phthalocyanine compound mixed crystal of Example 1.

Comparative Example 1 2,3 with a threo / erythro type composition ratio of 82/18
-Butanediol 6.25 parts (0.7 molar equivalents) 50
A phthalocyanine crystal was obtained in the same manner as in Example 1 except that the parts were replaced. This crystal had a peak at m / Z = 576 in the Mass spectrum. CuKα of this crystal
The X-ray diffraction spectrum for is shown in FIG.

The phthalocyanine crystal is disclosed in
It was produced according to the synthesis example disclosed in Japanese Patent No. 273775.

A photoconductor was prepared in the same manner as in Example 1, except that the same amount of the obtained phthalocyanine crystal was used instead of the phthalocyanine compound mixed crystal in Example 1.

Comparative Example 2 Phthalocyanine crystals were obtained in the same manner as in Comparative Example 1, except that the reaction was carried out at room temperature for 10 hours instead of heating under reflux for 7 hours. This crystal has a mass spectrum of m / Z
A peak was shown at = 648. The X-ray diffraction spectrum for CuKα of this crystal is shown in FIG.

The phthalocyanine crystal is disclosed in
It was produced according to the synthesis example disclosed in Japanese Patent No. 273775.

A photoconductor was prepared in the same manner as in Example 1 except that the same amount of the obtained phthalocyanine crystal was used instead of the phthalocyanine compound mixed crystal in Example 1.

Comparative Example 3 2,3 having a threo / erythro type composition ratio of 44/56
-Butanediol 6.25 parts (0.7 molar equivalents) 50
A phthalocyanine crystal was obtained in the same manner as in Example 2 except that the parts were replaced. This crystal had a peak at m / Z = 648 in the Mass spectrum. CuKα of this crystal
The X-ray diffraction spectrum for is shown in FIG.

The phthalocyanine crystal is disclosed in
It was produced according to the synthesis example disclosed in Japanese Patent No. 273775.

A photoconductor was prepared in the same manner as in Example 1 except that the same amount of the obtained phthalocyanine crystal was used instead of the phthalocyanine compound mixed crystal in Example 1.

Comparative Example 4 Phthalocyanine crystals were obtained in the same manner as in Comparative Example 3, except that the reaction was carried out at room temperature for 10 hours instead of heating under reflux for 7 hours. This crystal has a mass spectrum of m / Z
A peak was shown at = 648. The X-ray diffraction spectrum for CuKα of this crystal is shown in FIG.

The phthalocyanine crystal is disclosed in
It was produced according to the synthesis example disclosed in Japanese Patent No. 273775.

A photoconductor was prepared in the same manner as in Example 1, except that the same amount of the obtained phthalocyanine crystal was used instead of the phthalocyanine compound mixed crystal in Example 1.

Comparative Example 5 A phthalocyanine crystal was obtained in the same manner as in Example 1 except that 2,3-butanediol was not used. This crystal is Ma
A peak was shown at m / Z = 576 in the ss spectrum. The X-ray diffraction spectrum for CuKα of this crystal is shown in FIG.

The phthalocyanine crystal is a β-type crystal of oxytitanium phthalocyanine.

A photoconductor was prepared in the same manner as in Example 1 except that the same amount of the obtained phthalocyanine crystal was used instead of the phthalocyanine compound mixed crystal in Example 1.

Comparative Example 6 Example 1 was repeated except that the same amount of the oxytitanium phthalocyanine-amorphous dry powder obtained in Example 1 was used.
In the same manner as above, a photoconductor was made. FIG. 14 shows the X-ray diffraction spectrum for CuKα of the coating of the charge generating agent dispersion at this time. It can be seen that α-type oxytitanium phthalocyanine is obtained when pulverized and dispersed.

Each of the photoconductor samples obtained above was used as a paper analyzer EPA8100 (manufactured by Kawaguchi Electric Co., Ltd.).
Was evaluated using Incidentally, this evaluation method is described in JP-A-5-27.
This is in accordance with the evaluation method (evaluation 1) disclosed in Japanese Patent No. 3775.

The surface was charged under a discharge condition of −80 μA for 5 seconds, exposed to a surface potential immediately after charging [Va], a surface potential after standing for 5 seconds in the dark [Vi], and a surface illuminance of 2 (lux). Amount of exposure [E1 /
2 (lux · sec)] was calculated.

Further, the attenuation rate [D (%)] of the potential in a dark place was obtained by the formula: D = (Va−Vi) / Va × 100. The results are shown in Table 1.

[0167]

[Table 1]

In the above evaluation, the photoreceptor of the comparative example using the single crystal of the phthalocyanine compound having the specific structure seems to have excellent chargeability and charge retention ability, but E1 / 2
Obviously, it cannot be put to practical use by looking at it. However, since the electrophotographic photoreceptors of the present invention of Examples 1 and 2 use the characteristic specific mixed crystal, the basic electrophotographic characteristics such as chargeability, charge retention ability and sensitivity are not well balanced. As is clear from comparison with each comparative example, the sensitivity is extremely excellent.

The following description will be added to the reason why the phthalocyanine compound crystal of Example 1 or 2 is referred to as a mixed crystal or a crystal containing the same.

The present inventors obtained a reaction product by reacting an excess amount of 2,3-butanediol with oxytitanium phthalocyanine, and from the single crystal X-ray structural analysis of the reaction product, the reaction product of the reaction product was obtained. Compound G with the following molecular structure

[0171]

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It was confirmed that Further, from the analysis result, it was confirmed that the one obtained by rigorously reproducing the powder X-ray diffraction spectrum in agreement with the one shown in FIGS. 9 to 12 of Comparative Examples 1 to 4 described above. Therefore, the phthalocyanine compound crystal obtained in the comparative example is nothing but a single crystal of the compound G produced at an addition ratio of 1: 1.

However, the mixed crystal which is a feature of the present invention, for example, the crystal of the phthalocyanine compound of Example 1 described above, has a powder X-ray diffraction spectrum which is clearly different from that of the above Comparative Example, as shown in FIG. Further, the mass spectrum and the like confirmed that both oxytitanium phthalocyanine and compound G were mixed in the phthalocyanine compound crystal, and further, β-type oxytitanium phthalocyanine described in Comparative Example 5 and α-type oxy compound described in Comparative Example 6 were used. The phthalocyanine compound crystal is a mixed crystal of oxytitanium phthalocyanine and compound G because it shows a crystal form different from any existing crystal form oxytitanium phthalocyanine such as titanium phthalocyanine.

The mixed crystal is composed of oxytitanium phthalocyanine and compound G in a composition ratio of 30/70 to 70/30.
It is estimated to be a mixed crystal falling within the range of. Further, in the phthalocyanine crystal of Example 2, oxytitanium phthalocyanine and compound G were obtained by Mass spectrum and the like.
Both of them were observed, and as shown in FIG. 8, the powder X-ray diffraction spectrum pattern of the phthalocyanine compound crystal (mixed crystal) of Example 1 and that of β-type oxytitanium phthalocyanine were observed. It can be seen that it is a mixture of

By the way, in the above, the present invention has been specifically described by taking the mixed crystal of the phthalocyanine compound represented by the formula (1) and the oxytitanium phthalocyanine compound as an example.
The present invention includes the following embodiments, for example.

1. A phthalocyanine compound having an alkylene glycolate titanium ring having 4 or more carbon atoms,
An electrophotographic photoreceptor containing a mixed crystal with an oxytitanium phthalocyanine compound.

[0177] 2. A phthalocyanine compound having an alkylene glycolate titanium ring having 4 or more carbon atoms,
2. The electrophotographic photosensitive member according to 1 above, which is a dehydrated ring-closing compound of an alkylene glycol having 4 or more carbon atoms and an oxytitanium phthalocyanine compound.

[0178] 3. A phthalocyanine compound having an alkylene glycolate titanium ring having 4 or more carbon atoms,
2. The electrophotographic photosensitive member according to 1 above, which is a phthalocyanine compound having a 2,3-butylene glycolate titanium ring.

[0179] 4. 3. The electrophotographic photosensitive member according to 2 above, wherein the dehydrated ring-closing compound of an alkylene glycol having 4 or more carbon atoms and an oxytitanium phthalocyanine compound is a dehydrated ring-closed compound of a 2,3-butanediol compound and an oxytitanium phthalocyanine compound.

5. Oxytitanium and alkylene glycol having 4 or more carbon atoms, in which a mixed crystal is reacted at a reaction charge ratio of 0.5 to 1.5 mol of alkylene glycol having 4 or more carbon atoms per 1.0 mol of oxytitanium phthalocyanine compound. 2. The electrophotographic photosensitive member according to 1 above, which is a mixed crystal of a dehydrated ring-closing compound with a phthalocyanine compound and an oxytitanium phthalocyanine compound.

6. The mixed crystals were reacted at a reaction charge ratio of 0.5 to 1.5 mol of 2,3-butanediol per 1.0 mol of the oxytitanium phthalocyanine compound, 2,
2. The electrophotographic photosensitive member according to 1 above, which is a mixed crystal of a dehydration ring-closing compound of 3-butanediol and an oxytitanium phthalocyanine compound and an oxytitanium phthalocyanine compound.

7. The mixed crystal was reacted in an amount of 0.5 to 1.5 mol of 2,3-butanediol containing meso-2,3-butanediol as an essential component per 1.0 mol of the oxytitanium phthalocyanine compound. Two
2. The electrophotographic photosensitive member according to 1 above, which is a mixed crystal of a dehydration ring-closing compound of 3-butanediol and an oxytitanium phthalocyanine compound and an oxytitanium phthalocyanine compound.

8. 2,3-butanediol containing meso-2,3-butanediol as an essential component is
7. The electrophotographic photosensitive member according to 7 above, which is one of the four forms. Only meso-2,3-butanediol. meso-2,3-butanediol and (2R, 3
R)-(-)-2,3-Butanediol only binary mixture. meso-2,3-butanediol and (2S, 3
S)-(+)-2,3-Butanediol only binary mixture. meso-2,3-butanediol and (2R, 3
R)-(-)-2,3-butanediol and (2S, 3
S)-(+)-2,3-Butanediol only ternary mixture.

[0184]

The electrophotographic photoreceptor of the present invention has excellent sensitivity because it uses a mixed crystal of a phthalocyanine compound having an alkylene glycolate titanium ring having 4 or more carbon atoms and an oxytitanium phthalocyanine compound. It is extremely useful in practice.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view illustrating an example of a layer configuration of an electrophotographic photosensitive member according to the present invention.

FIG. 2 is a schematic cross-sectional view illustrating an example of a layer configuration of the electrophotographic photosensitive member according to the present invention.

FIG. 3 is a schematic cross-sectional view illustrating an example of a layer configuration of an electrophotographic photosensitive member according to the present invention.

FIG. 4 is a schematic cross-sectional view showing an example of the layer structure of the electrophotographic photosensitive member according to the present invention.

5 is an X-ray diffraction spectrum diagram for CuKα of the crude oxytitanium phthalocyanine obtained in Example 1. FIG.

FIG. 6 is an X-ray diffraction spectrum diagram for CuKα of oxytitanium phthalocyanine dry powder in an amorphous state obtained in Example 1.

7 is a mixed crystal CuKα according to the present invention obtained in Example 1. FIG.
2 is an X-ray diffraction spectrum diagram for FIG.

8 is an X-ray diffraction spectrum diagram for CuKα of a phthalocyanine crystal containing a mixed crystal according to the present invention obtained in Example 2. FIG.

FIG. 9: CuKα of phthalocyanine crystal obtained in Comparative Example 1
2 is an X-ray diffraction spectrum diagram for FIG.

FIG. 10: CuK of the phthalocyanine crystal obtained in Comparative Example 2
It is an X-ray diffraction spectrum figure with respect to (alpha).

11: CuK of phthalocyanine crystal obtained in Comparative Example 3 FIG.
It is an X-ray-diffraction spectrum figure with respect to (alpha).

FIG. 12 CuK of the phthalocyanine crystal obtained in Comparative Example 4
It is an X-ray-diffraction spectrum figure with respect to (alpha).

FIG. 13 CuK of the phthalocyanine crystal obtained in Comparative Example 5
It is an X-ray diffraction spectrum figure with respect to (alpha).

FIG. 14 is an X-ray diffraction spectrum diagram for CuKα of a coating film of the charge generator dispersion liquid used for the photoreceptor of Comparative Example 6.

[Explanation of symbols]

 1 Conductive Support 2 Charge Carrier Generation Layer 3 Charge Transport Layer 4a Photosensitive Layer 4b Photosensitive Layer 4c Photosensitive Layer 4d Photosensitive Layer 5 Charge Carrier Generating Material 6 Charge Transfer Medium 7 Electrophotographic Photosensitive Body 8 Photoconductive Material 9 Binder

Claims (6)

[Claims] (1) The following formula (1): (In the formula (1), R ¹ and R ² each independently represent a substituted or unsubstituted alkyl group, and Pc represents a substituted or unsubstituted phthalocyanine residue.) And an oxytitanium compound. An electrophotographic photosensitive member comprising a mixed crystal with a phthalocyanine compound. 2. The following formula (1): (In the formula (1), R ¹ and R ² each independently represent a substituted or unsubstituted alkyl group, and Pc represents a substituted or unsubstituted phthalocyanine residue.) Formula (2) And the following formula (3) (In the formulas (2) and (3), R ¹ and R ² each independently represent a substituted or unsubstituted alkyl group, and Pc represents a substituted or unsubstituted phthalocyanine residue). The electrophotographic photosensitive member according to claim 1, which is characterized in that. 3. The following formula (4): (In the formula (4), Pc represents a substituted or unsubstituted phthalocyanine residue.) An electrophotographic photoreceptor containing a mixed crystal of a phthalocyanine compound represented by the formula and an oxytitanium phthalocyanine compound. 4. The following formula (4): (In the formula (4), Pc represents a substituted or unsubstituted phthalocyanine residue.) Is a phthalocyanine compound represented by the following formula (5): And the following formula (6) (In the formulas (5) and (6), Pc represents a substituted or unsubstituted phthalocyanine residue.) The electrophotographic photosensitive member according to claim 3. . 5. The mixed crystal has a peak at at least 8.3, 24.7 and 25.1 degrees of Bragg angle (2θ ± 0.2 °) in an X-ray diffraction spectrum for CuKα. The electrophotographic photoreceptor according to claim 1, 2, 3, or 4. 6. An electrophotographic photoreceptor containing a mixed crystal of a phthalocyanine compound having an alkylene glycolate titanium ring having 4 or more carbon atoms and an oxytitanium phthalocyanine compound.